Original scientific paper

https://doi.org/10.5562/cca2706

Symmetrical and Unsymmetrical Schiff Bases Derived from 3,4-Diaminobenzophenone: Synthesis and Thermodynamics of Five Coordinated Tertiaryphosphine Cobalt(III) Complexes

Khosro Mohammadi ; Chemistry Department, Faculty of Sciences, Persian Gulf University, Bushehr 75169, I.R. Iran
Mozaffar Asadi ; Chemistry Department, College of Sciences, Shiraz University, Shiraz 71454, I.R. Iran
Moslem Setoodeh Khah ; Department of Inorganic Chemistry, Faculty of Chemistry, University of Kashan, Kashan, 87317-51167 I.R Iran
Hajar Sepehrpour ; Chemistry Department, College of Sciences, Shiraz University, Shiraz 71454, I.R. Iran

Abstract

Some new cobalt(III) complexes described as [Co(Chel)(PBu₃)]ClO₄ × H₂O where (Chel) is the deprotonated form of a series of symmetric and unsymmetrical Schiff base ligands containing 3,4-diaminobenzophenone (3,4-DABP) and substituted salicylaldehyde moieties and [Co(Chel)(PMePh₂)]ClO₄ × H₂O where (Chel) is [N’-(5-BrSalDABP)] were synthesized and characterized by 1H NMR, IR, UV–Vis spectroscopy, and elemental analysis. The formation constants and the thermodynamic parameters were determined spectrophotometrically for 1: 1 adduct formation of the new complexes as acceptor with some aliphatic amines such as benzylamine, n-butylamine, sec-butylamine and tert-butylamine as donors in DMSO solvent in constant ionic strength (I = 0.1 M NaClO4). The formation constants change according to the following trend due to the steric and the electronic factors of the cobalt(III) complexes: N’-5-OMe > N’-5-H > N’-5-Br > N’-5-Cl; N,N’-3-OMe > N,N’-4-Ome.
The trend of the formation constants of cobalt(III) Schiff base complexes toward a given donor according to the axial ligand is as follow: PBu3 > PMePh₂. Also, the following binding trend of the donors toward a given cobalt(III) Schiff base complex is obtained: benzylamine >
n-butylamine > sec-butylamine > tert-butylamine.

This work is licensed under a Creative Commons Attribution 4.0 International License.

Keywords

cobalt(III) complex; unsymmetrical Schiff base; thermodynamic; formation constants

Hrčak ID:

166911

URI

https://hrcak.srce.hr/166911

Publication date:

28.9.2016.

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